Fuel your engine with right nutrients!



As a Mechanical Engineer, I was always fascinated by automobiles. I was intrigued by how a simple automobile engine converts chemical energy of fuel into motion. Now that running is my newfound passion, I cannot help draw parallels between running and automobiles. Fundamentally, the two are very similar – both machines draw upon the energy from a fuel and convert it into kinetic energy (i.e. motion). However, the choice of right fuel is far more nuanced in the case of human running. This blog explores some key aspects around the choice of right nutrients to ‘fuel’ an athlete’s body.

Recreational runners are often obsessed with the idea of enriching their diet with carbohydrates and for right reasons. Carbohydrates, after all are the energy giving food and are critical for runners, especially long-distance runners. However, this obsession with ‘carb-loading’ at times leads them to neglect other important nutrients. An efficient runner needs right amounts of all types of nutrients – proteins, carbohydrates, fats, vitamins, minerals and water. The right amount and source of these may vary by the training needs. In this blog, I explore (and I deliberately use the word ‘explore’, as I am no an expert in this space and am myself trying to find the right answers) the following two important questions:
(i) why is each type of nutrient critical for a runner?
(ii) what are some good sources of proteins for vegetarians (something that I struggled with before finally finding a diet that suits me)?

So, let’s start with understanding the importance of different nutrients for a runner.

Carbohydrates
We all know that carbohydrates are the main energy giving food. Let us turn our attention to a slightly finer question – how much of it can we store in the body and how much do we need during a typical running event?

When we consume carbohydrates, these are broken into glucose and glycogen. Glucose is absorbed in the blood and circulates through the body – this is the most readily usable form of energy. Whatever energy is not needed immediately is stored in the form of glycogen reserves. A healthy human adult stores around 500gms of carbohydrate – around 400gms as muscle glycogen and around 100gms as glycogen in liver. Additionally, up to 25gms circulate through blood vessels in the form of glucose.

Now, let’s look at the next part of the question – how much carbohydrates do we need in a typical running event? Research indicates that in a typical running event a runner consumes around 3gms of carbohydrates per minute. This essentially implies that a well-nourished body has sufficient carbs to keep the body running for around 175 minutes [= (500 + 25) / 3]. Interestingly, this is quite close to the official cut-off time of 180 minutes for a half marathon.

If we look in terms of energy requirements, 500gms of carbohydrates represent around 2,000 Kcal of energy, while a runner like me (78kg) running a 21.1km stretch consumes around 1,780Kcal of energy (based on standard running calculators).

Two important observations before we move to the next nutrient:

1. The amount of glycogen that can be stored in a healthy body is limited. Any excess carbohydrates that we consume gets stored as fats – so, there is an upper limit to the amount of carb-loading that should or can be done. Any excess gets stored as unwanted fat.
2. Majority of glycogen (around 80%) is consumed in the muscle tissues. Hence, longer muscles are capable of storing more glycogen – next time you hear your coach say that stretching after running helps elongate and strengthen muscles, bear in mind this can potentially also increase your ability to store glycogen.

Some good sources of carbohydrates: Banana, low-fat yogurt, whole-grain bread, pasta, green vegetables and potatoes.

Fats
Human body comprises of much more fats as compared to carbohydrates. While the amount of carbohydrates a body can store is just around 500gms, around 10 - 20 percent of body weight (for a healthy person) can be made of fats. Research also indicates that 1 kg fat can provide around 9,000Kcal of energy. For a person like me (78kg), this means that my body can potentially store around 12 kg fats (or a source of 135,000Kcal energy). Now this is much more that what I would need to complete a half-marathon or a full marathon (or even an ultra-marathon).

However, the challenge is that unlike carbohydrates, fats cannot be readily consumed as energy sources. Deriving energy from fats is a relatively complex process. Fat is stored in the body in the form adipose tissue. To derive energy from adipose tissue, it first needs to be broken and transported to the tiring muscle. Moreover, releasing energy from the adipose tissue requires significant amount of oxygen. Typically, while running by the time there is a need to draw energy from adipose tissue (i.e. after depleting glycogen store), body is already breathless and availability of oxygen to release energy from adipose tissue becomes a limiting factor.  

Another important thing to note about fats is that these are of two types – saturated and unsaturated. Saturated fats are the ones that usually come from animal sources and carry significant health risks (including increased blood cholesterol level). Unsaturated fats are usually derived from plant sources and unlike saturated fats these fats do not carry health hazards. In fact, unsaturated fats provide some health benefits for heart.

So, what does this mean for us, the athletes? Primarily two things:

1. Unlike carbohydrates, fats are available in abundance in human body and there is no need for ‘fat-loading’. This is an important point as many people end up consuming fats under the garb of ‘carb-loading’ prior to the race day.
2. Amount of saturated fat intake should be limited but the diet should have appropriate level of unsaturated fats.

Some good sources of unsaturated fats (good fats): Olives, almonds, walnuts, nuts, peanut-butter, tofu, soy-milk, olive oil, soybean oil.

Water
Importance of staying well-hydrated in long-distance runs cannot be overemphasized. During long-distance runs body loses significant amount of water and sodium in the form of sweat. This loss of water and electrolytes is a common reason for the occurrence of muscle cramps.

Typical dietary intakes to avoid dehydration – 2 to 3 liters water per day and Enerzal (especially during the last few days leading to a running event).

Vitamins and Minerals
If we draw the analogy to the automobile engine that I started this blog with, vitamins and minerals are like lubricant oil for the automobile. Lubricant oil is not the fuel that provides energy for motion, but it is required to prevent wear and tear and ensure proper maintenance of the engine. Similarly, vitamins and minerals are nutrients that are required in small quantities for the body parts to function properly. These nutrients also help in strengthening the body’s immune system. There are different types of vitamins and minerals, each performing a specific function. Following table summarizes the most critical vitamins and minerals for an athlete and some common food sources. For brevity, I have confined the benefits to the ones most relevant for an athlete.

Proteins

Proteins are the nutrients that help in building muscle and expediting recovery / repair of damaged tissues during high intensity work-outs or long distance runs. Some runners tend to neglect protein, labelling it as ‘muscle-building’ food more appropriate for body builders. However, this is at best an incorrect practice. I usually think of protein intake in two phases:

1. During the months leading to running events (or during off-season): This is the ideal time to work on body fundamentals and build muscle strength. For instance, it helps to develop more muscle around forearms and wrists. This helps to provide greater propulsive thrust from the swinging of arms during running. Similarly, it is critical to conduct strength training to prepare the muscles (especially leg muscles such as calves, quads, hamstrings etc.) for the stress-impact these muscles will undergo during the running season.  
2. During the running season: If one is participating frequently in distance running events (say once in a month or two months), then the body needs quick recovery to repair the damaged tissues. Hence, here again, appropriate intake of proteins is critical.

An average human body needs around 0.8gms of protein per kg of body weight (daily). For athletes trying to build strength or recovering from a long-distance run, this requirement is considerably higher and is usually in the range of 1.4 to 1.6gms per kg of body weight. For me (78kgs), this implies a daily protein requirement of around 120gms. As a vegetarian (but consuming eggs), I often struggled to meet this requirement. However, with experimentation I think I have found a diet that largely serves my daily protein requirement – sharing below for the benefit of fellow vegetarian runners:

I hope the article provides some good 'food' for thought for runners looking to improve their nutrition to enhance their running performance.

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 Sundeep Singh: +91 - 98181 19794